This invention is intended for reducing the overall height of a computer keyboard, especially for laptop or handheld computers, when it is not in use. For mobile computers, both laptop and handheld computers, size is one of the most cited concerns. People want to have the size of the computer as small as possible but due to the ergonomic reasons, the size of those mobile computers on the horizontal plane is limited by the sizes of display and keyboard. Hence, the only space left to be shrunk is the vertical height of the computer. A thin keyboard is therefore desirable. A keyboard that is made of membrane switches is thin but it lacks the key stroke distance that makes it hard to be accepted by the general public. The keyboard to be disclosed here is a keyboard that gives a long key stroke distance compatible to a conventional desktop keyboard when in operation and remains thin when not in use. The keys on this keyboard will recess when the computer is turned off or the lid is closed, thereby providing an optimally thin device when not is use but providing optimal feel when being used.
There are a few US patents that mentioned something related to this invention:
(1) U.S. Pat. No. 4,795,888, "Variable Keystroke Pressure Apparatus", teaches a method of varying the pressure required for the keystroke by means of a variable pressure bladder. PA0 (2) U.S. Pat. No. 5,595,449, "Inflatable Keyboard", teaches an inflatable keyboard using a hand pump and deformable keys. PA0 (3) U.S. Pat. No. 5,459,461, "Inflatable Keyboard", teaches an inflatable keyboard using deformable keys.
There are a number of embodiments in this invention all with the intention of reducing the thickness of the keyboard while not in use by providing retractable keys. In the first embodiment, an inflatable air bag under the keys is used to raise the keys when in use and create the needed key stroke distance. The keys are conventional and not deformable. The air bag is self inflatable by the embedded springs under each keys. The keys will recess when the air is released or pumped out of the air bag. In a second embodiment, the keyboard is made up of two parallel sheets with springs between to enable the keystroke to be recorded and the key spring back to it's original position. When these sheets are sheared, the keyboard collapses to become very thin.
These and other objects, features and advantages will be apparent from the following more particular description of the preferred embodiments.